The phenotypic expression of a transgene in a plant is determined both by the structure of the gene itself and by its location in the plant genome. At the same time the presence of the transgene (in a foreign DNA) at different locations in the genome will influence the overall phenotype of the plant in different ways. The agronomically or industrially successful introduction of a commercially interesting trait in a plant by genetic manipulation can be a lengthy procedure dependent on different factors. The actual transformation and regeneration of genetically transformed plants are only the first in a series of selection steps, which include extensive genetic characterization, breeding, and evaluation in field trials, eventually leading to the selection of an elite event.
The unequivocal identification of an elite event is becoming increasingly important in view of discussions on Novel Food/Feed, segregation of GMO and non-GMO products and the identification of proprietary material. Ideally, such identification method is both quick and simple, without the need for an extensive laboratory set-up. Furthermore, the method should provide results that allow unequivocal determination of the elite event without expert interpretation, but which hold up under expert scrutiny if necessary.
GAT-ZM1 was selected as an elite event in the development of corn resistant to the herbicide Liberty®, by transformation of corn with plasmid pUC/Ac comprising the pat gene encoding tolerance to phosphinothricin. It is commercially sold as Liberty Link® maize, such as, for instance, Liberty Link® A6460LL sold by AgriGold/Akin Seed Company. The tools for use in simple and unequivocal methods for identification elite event GAT-ZM1 in biological samples are described herein.